It's very correct.
Hotmail was not intiially a microsoft company, it was bought out
by them.
Microsoft has tried, unsuccessfully and to the STRONG aggravation of the higher ups, three times to switch the hotmail infrastructure to windows. Every time has been a complete disaster. Windows cannot handle 1/10th the load that FreeBSD can. The hotmail BSD servers are extremely well setup..
I've got a couple of friends who are admins & programmers there, they're very badass.